It is known to provide, as a unit, a process kit comprising a photosensitive drum, a corona charger, a developing device and a cleaner. The unit is detachably mounted into the main body of an image forming apparatus, such as a copier or printer. One example of such a unit is disclosed in U.S. Pat. No. 4,591,258, which issued on May 27, 1986 in the names of F. Nishino et al and entitled "Safety Means for Process Kit".
Process kits similar to that shown in the Nishino et al patent have been marketed. They have established the economic viability of disposability of electrophotographic stations in the low volume printer and copier marketplace.
Other references have suggested the viability of disposable development stations without the other elements of the process kit of Nishino et al; see for example, Japanese Patent No. 56/779.
Obviously, to successfully market a system that includes disposable electrophotographic stations requires that those stations be mass produceable for low cost. Prior disposable stations such as the two mentioned above, use a single component developer which requires the loading of only a single compartment in this station with particulate material. However, the more traditional type of electrophotographic development utilizes a two-component developer made up of carrier particles and toner particles. The carrier and toner particles generally are mixed in a ratio of from two to ten percent toner by weight. As toner is depleted from the mix, it is added form a separate container generally containing only toner.
The problems associated with making a development station utilizing two-component developer inexpensively enough to allow it to be disposable are more severe than making a similarly disposable development station utilizing single-component developer.